2 ProblemTo find a cost effective solution to reduce the high level of THMs in the Killaloe Water System

3 Killaloe Water System Small system – only 90+ connectionsOwned by the Township of Killaloe, Hagarty and RichardsOperated by OCWAGroundwater wellsGUDI with in-situ filtrationTreatment for iron and manganese removalUV discharging to clearwellsLong residency time in clearwells and distribution system (3 to 5 days)THM levels near or over the 100 µg/L limitIndividual samples as high as 140 µg/L

4 Solution AVIVETM Water Treatment system from SanEcoTecUsing Huwa-San peroxide (HSP) New form of stabilized peroxide that maintains its residual (equivalent if not better than chlorine)NSF approved as a residual for drinking waterUsed successfully in Europe in drinking water since 2004Use HSP for secondary disinfection in the clearwells and distribution systemNo chlorine to produce THMs

5 Advantages of AVIVETM and HSPDoes not breakdown to form THMs or other chlorine based DBPsAttacks biofilm on pipe wallsVery strong oxidizerLonger lasting residualEasy to use for operatorsSimilar to sodium hypochloriteNo chlorine taste in the drinking waterSignificant consumer acceptance

6 Project Approach Met with MOE (regulators)Essential to get their buy-inSold the concept to the Township staff and CouncilIncluding our own operations staffNumerous consultation meetings with MOE Approvals and Health Unit staffUndertook baseline monitoring and samplingPublic notification

7 Baseline Monitoring and SamplingTHM formationHistorical THM concentration data available but not where along the process are the majority of the THMs formedUndertook jar testing to develop a baseline and confirm HSP worksATP testing of the existing systemBaseline of microbial activity within distribution systemUndertaken over a number of weeksOther testingHPC, Total Coliform, E.ColiMetals testing (copper, lead, iron, manganese)Residential hot water systemsMicrobiological testing includes Heterotrophic Plate Count (HPC), Total Coliform and E.Coli testingMetals testing includes Copper, Lead, Iron and Manganese testing (copper and lead were part of Schedule D of regulatory requirements)

8 ATP Testing - LuminultraMeasures Adenosine TriphosphateA chemical found in living microorganismsQuantitative indication of microbial activity in a sampleResults in 5 minutesIndication of the amount of biofilm on pipe wallsTesting equipment loaned to this project by LuminultraSampling and testing undertaken by staff from OCWA and Fleming College’s CAWTCentre for Alternative Wastewater Treatment – Brent Wootton

9 System Design Still need chlorine to achieve CT requirementsChlorine added to incoming raw well waterUsed residency time in contactor tanks and pipes (before UV) to achieve CTHSP added immediately after UV systemMeasure chlorine levels then adjust HSP dosing to quench chlorine + enough to maintain minimum secondary disinfection residual of 3 mg/LWith the quenching of the chlorine, THM formation immediately ceasesIssue of backwashing contactors with “peroxidated” waterFilter to waste until chlorine levels restoredThe Drinking Water License states that any result that indicates that the Hydrogen Peroxide residuals are below 1 milligram per litre in either the distribution system or plumbing connected to the distribution system, shall be considered an observation made under Section 16-4 (Duty to Report Other Observations)The MOE has stated that it wants to have residuals of less than 8 mg/L (NSF single product allowable concentration for hydrogen peroxide is 8 mg/L) in the distribution system, but would not be considered out of compliance.Therefore a target range of 1 mg/L to 8 mg/L

10 MOE Approvals Regulatory Relief Amendment to the DWWPSections from O. Reg. 170/03 under the Safe Drinking Water ActAmendment to the DWWPAdditional sampling and reporting for initial 3 monthsVoluntary sampling (i.e. residential hot water systems)Schedule 1-5(1), respecting the requirement for provision of water treatment equipment that is designed to be capable of secondary disinfection using chlorination or chloramination.Schedule 6-3(1)(a), respecting the collection of a sample for free chlorine residual at the same time and location at which a water sample is taken and tested for a microbiological parameter.2.1.3 Schedule 6-5(1), respecting the use of continuous monitoring equipment for sampling and testing, for free chlorine residual in a distribution sample.2.1.4 Schedule 6-7(1), respecting chlorine residual testing, for free chlorine residual in a distribution sample.2.1.5 Sections 7-2 (3) of Schedule 7, respecting the collection of distribution system samples and testing for free chlorine residual.2.1.6 Section 16-3 (1) 4 of Schedule 16, respecting the prescription of a result indicating a concentration of free chlorine residual of less than 0.05 milligrams per litre in a distribution grab sample or a domestic hot water plumbing sample taken as per Table 9 of this Schedule, as an adverse result under Section 18 of the Act.2.1.7 Section 18-4 (1, 2, 2.1) of Schedule 18, respecting corrective actions to be taken in the event of an adverse result for free chlorine residual in accordance with section 16-3(1) 4 of Schedule 16.

11 EquipmentVery similar to what is required for feeding and monitoring sodium hypochloriteChemical feed pumps (off the shelf)Peroxide residual monitors (supplied by Kramer)Handheld units for sampling in distribution system

12 ResultsHSP system was commissioned and went live in late November 2012Immediate THM reductionInitially down to µg/L rangeCurrent levels are in the µg/L rangeHSP residuals maintained throughout the distribution systemWater quality during the changeover was not affectedHAAs were also significantly reducedBefore 55 to 67 µg/L range; after 8.4 µg/L

15 ATP Testing Results Pre-HSP Post-HSPATP Results taken from 12 Coll St. (Residential Unit). Values shown here are not considered high ATP test results. Overall, it seemed that Killaloe did not have biofilm issues (pre or post).

16 Residential Hot Water Systems (Microbiological Activity)Pre-HSPPost-HSPHydrogen peroxide residual testing in hot water system is not part of MOE requirements however, a set of hot water testing was completed at the visitor centre from Dec 3-6 with a maximum residual reading of 2.5 mg/L on Monday, December 3rd. The treated water residual leaving the plant was 11.9 mg/L.Post-HSP

17 Conclusions Project a big success!Significant reduction in the DBPs producedProved HSP can retain a disinfecting residual equivalent to or better than chlorineSignificant consumer acceptance of their “new” tap waterWe finally have a viable alternative to chlorinating our water supplies